AM62P-Q1: GPMC module usage

Part Number: AM62P-Q1

Tool/software:

Hello, 

as below screenshot show, if we do not use GPMC function(no NOR/NAND flash), if these PINs(GPMC0_AD0~GPMC0_AD15) must connect to VSS(if these PINs not used)? or can we just leave it open? 

also, these multi_function PINs can be used as other function as below show, right?